<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <style>
    .c1{
      color:red;
    }
    #c2{
      color:gold;
    }
    .yy li{
      color: pink;
    }
    .yy a{
      color:dodgerblue;
    }
    input[type='text'] {
      border:1px solid red;
    }
    .v1[xx='456'] {
      color:gold;
    }

  </style>
</head>
<body>

  <h1>登录页面</h1>

  <div class="c1">中国</div>
  <div id="c2">广西</div>
  <div >联通</div>
  <ul>
    <li>北京</li>
    <li>上海</li>
    <li>深圳</li>
  </ul>
  <input type="text">
  <input type="password">
  <div class="v1" xx="123">s</div>
  <div class="v1" xx="456">f</div>
  <div class="v1" xx="999">a</div>

  <div class="yy">
    <a href="">百度</a>
    <li>美国</li>
    <li>日本</li>
    <li>韩国</li>
  </div>

</body>
</html>